<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title></title>
  </head>
  <body>
    <div id="app">
      <div v-once>初始值：{{count}}</div>
      <div>累加值：{{count}}</div>
      <button @click="count++">加一</button>
    </div>
    <script src="./vue.js"></script>
    <script>
      const vm = new Vue({
        el: '#app',
        data: {
          count: 100
        },
        methods: {}
      })
    </script>
  </body>
</html>